Hot press molding device for silicon nitride substrate

Abstract

The utility model relates to the technical field of silicon nitride substrate processing, and discloses a silicon nitride substrate hot press molding device, which comprises a rack body, mounting grooves are formed in two ends of a top operation table of the rack body, and a rectangular through groove is formed in the middle of the top operation table; the forming mechanism is fixedly welded to the middle of the bottom end of the operation table on the top of the rack body and located below the rectangular through groove. The fixed lifting mechanism is fixedly arranged on the inner side of a supporting leg at the top of the rack body; through mutual cooperation of the forming mechanism and the fixed lifting mechanism, the bottom of the forming mechanism can be supported under the adjusting action of the fixed lifting mechanism after adjustment is completed through the forming mechanism in the actual use process, so that internal parts of the forming mechanism are in a stable state, and the forming mechanism is convenient to use. Therefore, the silicon nitride substrate can be stably compacted and heated, so that the silicon nitride substrate can be quickly processed, and the operation is convenient.

Description

TECHNICAL FIELD

[0001] The utility model relates to silicon nitride substrate processing technical field especially is silicon nitride substrate hot press forming device. BACKGROUND

[0002] With the development of human technology, more and more motor-driven equipment is developed, such as airplanes, high-speed trains, ships and electric vehicles, which are all developing towards electric power driving, and the significance is environmental protection, pollution reduction, energy saving and high automation. Because the power of electric power driving is large, the insulated gate bipolar transistor (IGBT) for controlling the electric motor currently uses a silicon nitride high-thermal-conductivity ceramic substrate. In the processing of the silicon nitride ceramic substrate, a hot press forming step is needed, and three layers of blank, i.e. upper cover material, substrate material and lower cover material, are usually used for hot press forming.

[0003] After searching, a hot press forming device for silicon nitride substrate production is disclosed in CN222407572U, which comprises a first drive cylinder, a pressing plate, a mold box, a heat preservation mechanism, a moving plate, a lifting mechanism, a second drive cylinder, a push plate and a material collecting mechanism. The top of the box body is provided with the first drive cylinder. The connecting rod of the first drive cylinder is connected with the pressing plate. The middle part of the fixed plate is provided with the mold box. The outer side of the mold box is provided with the heat preservation mechanism. The bottom of the mold box is a slidingly connected moving plate. The moving plate is provided with the lifting mechanism. One side above the fixed plate is provided with the second drive cylinder. The connecting rod of the second drive cylinder is connected with the push plate. The other side above the fixed plate is provided with a discharge port. The discharge port is provided below the material collecting mechanism. The rear end of the fixed plate is provided with a discharge track.

[0004] The above-mentioned technical solution has certain beneficial effects, but in the actual use process, the torque of the servo motor is not enough due to the mutual meshing connection between the rack and the gear for transmission, and the moving plate cannot be in a stable state during the process of pressing and compacting the raw material. Therefore, we propose a silicon nitride substrate hot press forming device. UTILITY MODEL CONTENTS

[0005] In view of the above problems, the utility model provides a silicon nitride substrate hot press forming device, which can solve the problems existing in the background art.

[0006] The utility model provides the following technical scheme: a silicon nitride substrate hot press forming device, comprising:

[0007] The top operation table of the rack body is provided with a rectangular through slot in the middle part, and the rack body is provided with a mounting groove at both ends of the top operation table.

[0008] The forming mechanism is fixedly welded to the bottom center of the top operating table of the frame body and located below the rectangular through groove;

[0009] A fixed lifting mechanism is fixedly installed on the inner side of the top support leg of the frame body;

[0010] The compaction heating mechanism is fixedly installed on the top of the operating table at the top of the frame body;

[0011] The fastening mechanism is symmetrically arranged below the mounting grooves at both ends of the top operating platform of the frame body;

[0012] The raw material collection mechanism is installed inside the mounting grooves at both ends of the top operating platform of the frame body, and its end is located inside the connecting fastening mechanism.

[0013] The raw material leveling mechanism is installed at the top front end of the top operating table of the frame body and is located at the bottom inside the compaction heating mechanism;

[0014] A feeding guide frame is installed at the top rear end of the top operating platform of the frame body;

[0015] Furthermore, the molding mechanism includes a molding outer box located below the rectangular through groove. A movable base plate is movably provided on the inner side of the molding outer box. A fixed connecting column is welded to the bottom end of the movable base plate. A rectangular through hole adapted to the fixed connecting column is opened at the bottom end of the molding outer box. An electric telescopic rod is provided in the middle of the bottom end of the molding outer box. A through hole adapted to the output end of the electric telescopic rod is opened in the middle of the bottom end of the molding outer box. The output end of the electric telescopic rod is fixedly connected to the middle of the bottom end of the movable base plate.

[0016] Furthermore, the fixed support mechanism includes a fixed mounting plate located inside the support leg, the fixed...

[0017] The top of the mounting plate is symmetrically provided with a first frame. A first servo motor is bolted to one end of the first frame. The first servo motor has a first guide groove inside. The first frame has a circular through hole inside. The output end of the first servo motor is provided with a first threaded rod. The first threaded rod is located inside the circular through hole inside the first frame. The other end of the first threaded rod is provided with a first limiting plate. The side of the first limiting plate near the first frame is in contact with the side of the first frame away from the first servo motor. A movable support block is threadedly sleeved on the outer surface of the first threaded rod. The outer surface of the bottom end of the movable support block is slidably in contact with the inner side of the first guide groove. A lifting step is provided on the top of the movable support block.

[0018] Furthermore, the compaction heating mechanism includes symmetrically located support mounting columns at the end of the operating platform at the top of the frame body. A connecting top plate is welded to the top of the support mounting column. A fixed reinforcing block is provided between the bottom edge of the connecting top plate and the outer top of the support mounting column. A hydraulic rod is provided at the middle of the top of the connecting top plate. A connecting extension rod is fixedly connected to the output end of the hydraulic rod. A compaction heating block is provided at the bottom end of the connecting extension rod.

[0019] Furthermore, the connection and fastening mechanism includes a fixed limiting block, which is located below the ends of the mounting grooves at both ends of the top operating platform of the frame body. The bottom of the fixed limiting block is provided with a threaded sleeve, and a fastening bolt is threadedly connected inside the threaded sleeve. A through hole adapted to the fastening bolt is opened inside the fixed limiting block.

[0020] Furthermore, the raw material collection mechanism includes a collection box located inside the mounting grooves at both ends of the top of the frame body. The top of the front and rear sides of the collection box are provided with movable locking blocks. A connecting handle is provided on the upper part of the side of the collection box away from the frame body. The movable locking blocks are located inside the fixed limiting blocks.

[0021] Furthermore, the raw material smoothing mechanism includes a second frame, one end of which is equipped with a second servo motor. A second guide groove and a circular through hole are formed inside the second frame. A second threaded rod is fixedly connected to the output end of the second servo motor.

[0022] Inside the circular through hole of the second frame, a second limiting plate is fixedly connected to the end of the second threaded rod away from the second servo motor. The side of the second limiting plate near the second frame is in contact with the end of the second frame away from the second servo motor. A movable mounting block is connected to the outer surface of the second threaded rod by a thread. A connecting smoothing arm is fixedly connected to one side of the movable mounting block. The movable mounting block and the second frame are in slidable contact. The bottom of the connecting smoothing arm is in slidable contact with the top of the operating table on the top of the machine body.

[0023] The beneficial effects of this utility model are:

[0024] 1. Through the cooperation between the molding mechanism and the fixed support mechanism, the bottom of the molding mechanism can be supported by the fixed support mechanism after the molding mechanism is adjusted during actual use. This ensures that the internal components of the molding mechanism are in a stable state, thereby stably compacting and heating the silicon nitride substrate, enabling rapid processing and convenient operation.

[0025] 2. Through the cooperation of the connecting and fastening mechanism, the raw material collection mechanism and the raw material smoothing mechanism, the connecting and fastening mechanism can install and fix the raw material collection mechanism, so that the raw material collection mechanism can be used stably. Then, after the raw material is added, the raw material smoothing mechanism can smooth the raw material and push the excess raw material to the inside of the raw material collection mechanism for collection. The raw material smoothing mechanism has a long stroke and is reciprocating, and can move different materials in opposite directions. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of a silicon nitride substrate hot pressing forming apparatus according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the molding mechanism of a silicon nitride substrate hot pressing molding apparatus according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the fixed support mechanism of a silicon nitride substrate hot pressing forming device according to an embodiment of the present invention;

[0029] Figure 4 This invention relates to a frame body and raw material for a silicon nitride substrate hot pressing molding apparatus.

[0030] Schematic diagram of the exploded structure of the collection mechanism;

[0031] Figure 5 This is a schematic diagram of the raw material smoothing mechanism of a silicon nitride substrate hot pressing molding apparatus according to an embodiment of this utility model.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Frame body;

[0034] 2. Molding mechanism; 21. Molding outer box; 22. Movable base plate; 23. Fixed connecting column; 24. Electric telescopic rod;

[0035] 3. Fixed lifting mechanism; 31. Fixed mounting plate; 32. First frame; 33. First servo motor; 34. First threaded rod; 35. First limiting plate; 36. First guide groove; 37. Moving support block; 38. Lifting steps;

[0036] 4. Compacting heating mechanism; 41. Supporting mounting column; 42. Connecting top plate; 43. Fixing reinforcing block; 44. Hydraulic rod; 45. Connecting extension rod; 46. Compacting heating block;

[0037] 5. Connecting and fastening mechanism; 51. Fixed limit block; 52. Threaded sleeve; 53. Fastening bolt;

[0038] 6. Raw material collection mechanism; 61. Collection box; 62. Movable card block; 63. Connecting handle;

[0039] 7. Raw material smoothing mechanism; 71. Second frame; 72. Second guide groove; 73. Second servo motor; 74. Second threaded rod; 75. Second limit plate; 76. Movable mounting block; 77. Connecting smoothing arm;

[0040] 8. Feeding guide frame. Detailed Implementation

[0041] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0042] Example:

[0043] Reference Figures 1-5 This utility model provides a silicon nitride substrate hot pressing forming apparatus, comprising:

[0044] The frame body 1 has mounting grooves at both ends of the top operating platform and a rectangular through groove in the middle of the top operating platform.

[0045] The forming mechanism 2 is fixedly welded to the bottom center of the top operating table of the frame body 1 and is located below the rectangular through groove;

[0046] The fixed lifting mechanism 3 is fixedly installed on the inside of the top support leg of the frame body 1;

[0047] The compaction and feeding mechanism 4 is fixedly installed on the top of the operating platform at the top of the frame body 1;

[0048] The fastening mechanism 5 is symmetrically arranged below the mounting grooves at both ends of the top operating table of the frame body 1;

[0049] The raw material collection mechanism 6 is installed inside the mounting grooves at both ends of the top operating table of the frame body 1, and its end is located inside the connecting fastening mechanism 5.

[0050] The raw material leveling mechanism 7 is installed at the top front end of the top operating table of the frame body 1 and is located at the bottom inside the compaction heating mechanism 4.

[0051] The feeding guide frame 8 is installed at the top rear end of the top operating table of the frame body 1;

[0052] The molding mechanism 2 includes a molding outer box 21 located below a rectangular through slot. A movable base plate 22 is movably provided inside the molding outer box 21. A fixed connecting column 23 is welded to the bottom end of the movable base plate 22. A rectangular through hole adapted to the fixed connecting column 23 is opened at the bottom end of the molding outer box 21. An electric telescopic rod 24 is provided in the middle of the bottom end of the molding outer box 21. A through hole adapted to the output end of the electric telescopic rod 24 is opened in the middle of the bottom end of the molding outer box 21. The output end of the electric telescopic rod 24 is fixedly connected to the middle of the bottom end of the movable base plate 22, so that the electric telescopic rod 24 can push the movable base plate 22 upward, so that the movable base plate 22 can move inside the molding outer box 21. At the same time, it drives the fixed connecting column 23 to move inside the bottom end of the molding outer box 21, thereby adjusting the height of the movable base plate 22, which is convenient to operate.

[0053] The fixed lifting mechanism 3 includes a fixed mounting plate 31 located inside the support leg. A first frame 32 is symmetrically arranged at the top of the fixed mounting plate 31. A first servo motor 33 is bolted to one end of the first frame 32. A first guide groove 36 is formed inside the first servo motor 33. A circular through hole is formed inside the first frame 32. A first threaded rod 34 is provided at the output end of the first servo motor 33. The first threaded rod 34 is located inside the circular through hole inside the first frame 32. A first limiting plate is provided at the other end of the first threaded rod 34.

[0054] 35. The side of the first limiting plate 35 closest to the first frame 32 is in contact with the end of the first frame 32 furthest from the first servo motor 33. A movable support block 37 is threadedly sleeved on the outer surface of the first threaded rod 34. The outer surface of the bottom end of the movable support block 37 slides in contact with the inner side of the first guide groove 36. A lifting step 38 is provided on the top of the movable support block 37, so that after the fixed connecting column 23 moves upward a certain distance, the first servo motor 33 can drive the first threaded rod 34, so that the first threaded rod 34 and the first limiting plate 35 can rotate. Then the movable support block 37 can move on the outer surface of the first threaded rod 34 and the inner side of the first guide groove 36, so that the position of the movable support block 37 and the lifting step 38 changes, so that the top of the lifting step 38 is in contact with the bottom end of the fixed connecting column 23, which can stably push the fixed connecting column 23 and is easy to operate.

[0055] The compaction heating mechanism 4 includes symmetrical support mounting columns 41 located at the top end of the operating table of the machine frame body 1. A connecting top plate 42 is welded to the top of the support mounting column 41. A fixed reinforcing block 43 is provided between the bottom edge of the connecting top plate 42 and the outer top of the support mounting column 41. A hydraulic rod 44 is provided at the middle of the top of the connecting top plate 42. A connecting extension rod 45 is fixedly connected to the output end of the hydraulic rod 44. A compaction heating block 46 is provided at the bottom end of the connecting extension rod 45, which allows the hydraulic rod 44 to push the connecting extension rod 45 and the compaction heating block 46 downwards. This allows the compaction heating block 46 to move through the rectangular through hole in the middle of the operating table of the top of the machine frame body 1 towards the inside of the forming outer box 21, compacting and heating the raw material located inside the forming outer box 21 and on the top of the movable base plate 22. The operation is convenient.

[0056] The fastening mechanism 5 includes a fixing block 51, located below the ends of the mounting grooves at both ends of the operating platform on the top of the frame body 1. A threaded sleeve 52 is provided at the bottom of the fixing block 51, and a fastening bolt 53 is threadedly connected inside the threaded sleeve 52. A through hole adapted to the fastening bolt 53 is provided inside the fixing block 51, allowing the raw material collecting mechanism 6 to rotate the fastening bolt 53 when it is inside the fastening mechanism 5. This allows the fastening bolt 53 to rotate inside the threaded sleeve 52 and move inside the fixing block 51, enabling the top of the fastening bolt 53 to contact the raw material.

[0057] The collecting mechanism 6 is squeezed and fixed, which enables the raw material collecting mechanism 6 to be used stably and is easy to operate.

[0058] The raw material collection mechanism 6 includes a collection box 61 located inside the mounting grooves at both ends of the top of the frame body 1. Movable locking blocks 62 are provided at the top of both the front and rear sides of the collection box 61. A connecting handle 63 is provided on the upper part of the side of the collection box 61 away from the frame body 1. The movable locking blocks 62 are located inside the fixed limiting blocks 51, facilitating the movement of the connecting handles 63. This allows the collection box 61 and the movable locking blocks 62 to move, enabling the movable locking blocks 62 to engage inside the fixed limiting blocks 51. This allows the collection box 61 to be positioned inside the mounting grooves at both ends of the operating platform at the top of the frame body 1, facilitating installation and use.

[0059] The raw material smoothing mechanism 7 includes a second frame 71. A second servo motor 73 is located at one end of the second frame 71. A second guide groove 72 and a circular through hole are formed inside the second frame 71. A second threaded rod 74 is fixedly connected to the output end of the second servo motor 73. The second threaded rod 74 is located inside the circular through hole of the second frame 71. A second limiting plate 75 is fixedly connected to the end of the second threaded rod 74 away from the second servo motor 73. The side of the second limiting plate 75 closest to the second frame 71 is in contact with the end of the second frame 71 away from the second servo motor 73. A movable mounting block 76 is threadedly connected to the outer surface of the second threaded rod 74. A connecting smoothing arm 77 is fixedly connected to one side of the movable mounting block 76. The movable mounting block 76 and the second frame 71 are in slidable contact. The bottom of the connecting smoothing arm 77 is in slidable contact with the top of the operating table on the top of the machine body 1, facilitating the second servo motor 73 to drive the second threaded rod 74. The second limiting plate 75 can rotate, allowing the movable mounting block 76 to move on the outer side of the second threaded rod 74 and the inner side of the second guide groove 72, driving the connecting smoothing arm 77 to move on the surface of the operating table at the top of the frame body 1, thereby smoothing the raw material and pushing excess raw material, causing the excess raw material to move towards the inner side of the collection box 61, where the collection box 61 collects the excess raw material, making the operation convenient.

[0060] The working principle of this utility model is as follows: During use, firstly, the handle 63 is moved, causing the collection box 61 and the movable locking block 62 to move, so that the movable locking block 62 is positioned inside the fixed limiting block 51, and the collection box 61 is positioned inside the mounting grooves at both ends of the operating platform on the top of the frame body 1. Then, the fastening bolt 53 is rotated, allowing it to rotate inside the threaded sleeve 52 and move upwards, so that the top of the fastening bolt 53 can press and fix the movable locking block 62, ensuring stable use of the collection box 61. Next, the electric telescopic rod 24 pushes the movable base plate 22 upwards, causing the fixed connecting column 23 to move. Simultaneously, the first servo motor 33 drives the first threaded rod 34, causing the first threaded rod 34 and the first limiting plate 35 to rotate. Then, the movable support block 37 moves on the outer surface of the first threaded rod 34 and the inner surface of the first guide groove 36, causing the movable support block 37 and the lifting step 38 to move. The position is changed so that the top of the lifting step 38 and the bottom of the fixed connecting column 23 fit together, which can stably push the fixed connecting column 23. Then, the material is guided by the feeding guide frame 8, so that the material can move to the inside of the molding outer box 21 and the top of the moving base plate 22. The second servo motor 73 can drive the second threaded rod 74, so that the second threaded rod 74 and the second limit plate 75 can rotate, so that the moving mounting block 76 can move on the outer surface of the second threaded rod 74 and the inner side of the second guide groove 72, driving the connecting smoothing arm 77 to move. The connecting smoothing arm 77 can move on the surface of the operating table at the top of the frame body 1, thereby smoothing the material and pushing the excess material, so that the excess material moves to the inside of the collection box 61 and is collected by the collection box 61. At this time, the connecting smoothing arm 77 is on one side of one of the collection boxes 61. At this time, the hydraulic rod 44 can move the connecting extension rod 45. The compaction heating block 46 is pushed downwards, allowing it to move through the rectangular through-hole in the middle of the top operating table of the frame body 1 towards the inside of the molding outer box 21. This compacts and heats the raw material located inside the molding outer box 21 and on top of the movable base plate 22, processing the lower plate of the silicon nitride substrate. Then, the fixing and lifting mechanism 3 is adjusted so that it does not move away from the fixed...

[0061] The connecting column 23 is lifted, and the electric telescopic rod 24 can retract, causing the movable base plate 22 to move downward a certain distance. The fixed lifting mechanism 3 is adjusted again so that it can lift the fixed connecting column 23. The above operation is repeated. At this time, the connecting smoothing arm 77 is on one side of the other collection box 61, so that different raw materials can be collected. At the same time, the middle plate of the silicon nitride substrate can be formed. Finally, the above operation is repeated to form the upper plate of the silicon nitride substrate. The overall structure is simple and the operation is convenient and quick.

[0062] The above embodiments merely illustrate specific implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. A silicon nitride substrate hot press forming apparatus characterized by comprising: The utility model relates to a kind of forming mechanism, which is fixedly welded in the middle part of the bottom of the top operating platform of the rack body (1), and is located below the rectangular through slot. The utility model relates to a kind of fixed lifting mechanism, which is fixedly arranged in the inner side of the top supporting leg of the rack body (1). The utility model relates to a kind of compaction heating mechanism, which is fixedly arranged on the top of the top operating platform of the rack body (1). The utility model relates to a kind of connecting fastening mechanism, which is symmetrically arranged below the installation recess of the both ends of the top operating platform of the rack body (1). The utility model relates to a kind of raw material collection mechanism, which is installed in the inner side of the installation recess of the both ends of the top operating platform of the rack body (1), and the end is located in the inner side of the connecting fastening mechanism (5). The utility model relates to a kind of raw material smoothing mechanism, which is installed on the top front end of the top operating platform of the rack body (1), and is located in the inner side bottom of the compaction heating mechanism (4). The utility model relates to a kind of feeding guide frame, which is installed on the top rear end of the top operating platform of the rack body (1). The utility model relates to a kind of fixed lifting mechanism, which is fixedly arranged in the inner side of the top supporting leg of the rack body (1). The utility model relates to a kind of compaction heating mechanism, which is fixedly arranged on the top of the top operating platform of the rack body (1).

2. The apparatus according to claim 1, wherein: The utility model relates to a kind of connecting fastening mechanism, which is symmetrically arranged below the installation recess of the both ends of the top operating platform of the rack body (1).

3. The apparatus for hot press molding of a silicon nitride substrate according to claim 1, wherein: The utility model relates to a kind of raw material collection mechanism, which is installed in the inner side of the installation recess of the both ends of the top operating platform of the rack body (1), and the end is located in the inner side of the connecting fastening mechanism (5). The utility model relates to a kind of raw material smoothing mechanism, which is installed on the top front end of the top operating platform of the rack body (1), and is located in the inner side bottom of the compaction heating mechanism (4). The utility model relates to a kind of feeding guide frame, which is installed on the top rear end of the top operating platform of the rack body (1).

4. The apparatus for hot press molding of a silicon nitride substrate according to claim 1, wherein: The compaction heating mechanism (4) comprises a support mounting column (41) symmetrically located at the top operating table end of the rack body (1), a connecting top plate (42) is welded at the top of the support mounting column (41), a fixed reinforcing block (43) is arranged between the bottom edge of the connecting top plate (42) and the outer top end of the support mounting column (41), a hydraulic rod (44) is arranged at the middle of the top end of the connecting top plate (42), a connecting lengthening rod (45) is fixedly connected to the output end of the hydraulic rod (44), and a compaction heating block (46) is arranged at the bottom end of the connecting lengthening rod (45).

5. The apparatus for hot press molding of a silicon nitride substrate according to claim 1, wherein: The connecting and fastening mechanism (5) comprises a fixed limiting block (51) located below the end of the mounting groove at both ends of the top operating table of the rack body (1), a threaded sleeve (52) is arranged at the bottom of the fixed limiting block (51), a fastening bolt (53) is threadedly connected in the threaded sleeve (52), and a through hole matched with the fastening bolt (53) is formed in the fixed limiting block (51).

6. The apparatus for hot press molding of a silicon nitride substrate according to claim 5, wherein: The raw material collecting mechanism (6) comprises a collecting box (61) located in the inner side of the mounting groove at both ends of the top of the rack body (1), movable clamping blocks (62) are arranged at the top end of the front and rear sides of the collecting box (61), a connecting handle (63) is arranged on the upper side of the side of the collecting box (61) away from the rack body (1), and the movable clamping blocks (62) are located on the inner side of the fixed limiting block (51).

7. The apparatus for hot press molding of a silicon nitride substrate according to claim 1, wherein: The raw material smoothing mechanism (7) comprises a second frame (71), one end of the second frame (71) is provided with a second servo motor (73), a second guide groove (72) is formed in the second frame (71), a circular through hole is formed in the second frame (71), a second threaded rod (74) is fixedly connected to the output end of the second servo motor (73), the second threaded rod (74) is located on the inner side of the circular through hole in the second frame (71), a second limiting disc (75) is fixedly connected to the end of the second threaded rod (74) away from the second servo motor (73), the second limiting disc (75) is close to one side of the second frame (71) and the end of the second frame (71) away from the second servo motor (73), a movable mounting block (76) is threadedly connected to the outer side of the surface of the second threaded rod (74), a connecting smoothing arm (77) is fixedly connected to one side of the movable mounting block (76), the movable mounting block (76) and the second frame (71) are slidably attached to each other, and the bottom of the connecting smoothing arm (77) and the top of the top operating table of the rack body (1) are slidably attached to each other.

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